Sealant composition for releasable shingle

ABSTRACT

A sealant composition for roofing shingles that includes a base asphalt, a linear and/or a radial copolymer, oil, and a wax is provided. The linear copolymer has an A-B di-block or an A-B-A tri-block structure. The radial copolymer may have an (A-B) n  radial structure, where n is at least 4, or a tri-block (A-B-A) radial structure having from 4 to 8 arms. Blocks A and B may individually represent (1) styrene and butadiene or (2) styrene and isoprene. The oil is a petroleum-based oil that both “softens” the asphalt and reduces the viscosity of the sealant composition. The wax may be a bis-stearamide wax. Additionally, the sealant composition may be reacted with elemental sulfur to crosslink the copolymer blend. The sealant composition seals at temperatures lower than conventional sealants and promotes the easy release of the shingle from a shingle bundle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to and claims domestic priority benefitsfrom U.S. Provisional Patent Application Ser. No. 61/161,996 entitled“Low Temperature Shingle Sealant Composition” filed Mar. 20, 2009 andU.S. Provisional Patent Application Ser. No. 61/162,111 entitled “LowTemperature Shingle Sealant Composition” filed Mar. 20, 2009, the entirecontents of which are expressly incorporated herein by reference intheir entireties.

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

The present invention relates generally to roofing shingles, and moreparticularly, to an asphaltic sealant that seals at temperatures lowerthan conventional sealants and that promotes the easy release of theshingle from a shingle bundle.

BACKGROUND

Asphalt-based roofing materials, such as roofing shingles, roll roofing,and built-up roofing, are installed on the roofs of buildings andresidential dwellings to provide protection from the elements. The useof adhesives, including asphaltic compounds, to provide a bond betweenroofing shingles when they are attached to a roof is well-known. Duringa typical shingle manufacturing process, a pattern of adhesive isapplied to the headlap portion of the shingles so that the tab portionof the subsequently laid course of shingles on the roof will adhere tothe headlap portion of the lower course. This seal is to help preventwind from uplifting the shingles.

To seal properly, most conventional sealants or adhesives requirerelatively high roof temperatures. Indeed, many conventional adhesivesrequire roof temperatures of about 135° F. or higher to activate thesealant. In relatively colder climates, these roof temperatures may notbe reached until seasons subsequent to installation, which conceivablycould be months later. Thus, under conditions where relatively lowtemperatures do not permit proper sealing of the adhesive, the shinglesmay not be properly sealed. Another problem with conventional sealantsis that colder temperatures tend to cause the sealant on the sealedshingles to become brittle and crack, resulting in bond failure.

A further problem associated with conventional sealants is that thesealant may bond the shingles together when they are in a packaged orbundled formation, such as, for example, for shipping and storing. Ashingle having thereon an overly aggressive sealant will not only bondto the tab portion of the shingle when placed on a roof, it will alsobond to the release tape of the adjacent shingle within the packagedshingle bundle. Such bonding may not only damage the shingle as theshingles are pried apart, it may cause frustration to the consumertrying to separate the shingles.

Although attempts have been made to address the temperature sealingproblem of conventional adhesives and the over aggressiveness of thesealants, there remains a need in the art for an asphalt sealant thatprovides a quick and good seal at low roof temperatures, that is notoverly aggressive so as to bond to the release tape in a packagedformation, that has a high bond strength to provide good resistance toshingle uplift, that does not pose any additional health or safetyissues, is cost effective, and where the performance of the sealant issustainable over time.

SUMMARY OF THE INVENTION

In some embodiments, an adhesive sealant composition that includes abase asphalt, a linear copolymer and/or a radial copolymer, an oil, anda wax is provided. The base asphalt used in the inventive sealantcomposition may be a viscosity graded asphalt, such as AC-10 or AC-20,or a paving graded asphalt, such as PG58 or PG64. The radial copolymermay have an (A-B)_(n) radial structure, where n is an integer of atleast 4, or a tri-block (A-B-A) radial structure having from 4-8 arms.The linear copolymer may have an A-B di-block structure or an A-B-Atri-block structure. Blocks A and B may individually represent (1)styrene and butadiene or (2) styrene and isoprene. The oil is apetroleum-based oil that both “softens” the asphalt in the compositionand reduces the viscosity of the adhesive sealant composition. In someexemplary embodiments, the sealant composition also contains a wax. Suchas a bis-stearamide wax. The wax may be N, N′-ethylenebis-stearamide,which is commercially available from Lonza, Inc. The inventive sealantcomposition maintains sufficient tack at lower temperatures to provide agood bond during installation. In addition, the sealant compositionseals the shingles at roof temperatures that are lower than conventionalsealants and provides good resistance to shingle uplift.

In other embodiments, roofing shingles that includes a tab portion,upper headlap portion, a release tape positioned on a rear portion ofthe headlap portion are provided, and a sealant composition positionedon a rear portion of the tab portion are provided. The sealantcomposition includes (1) a hydrocarbonaceous material, (2) a linearcopolymer having an A-B di-block or an A-B-A tri-block structure and/ora radial copolymer that is selected from a block copolymer having an(A-B)_(n) radial structure where n is an integer of at least 4 and ablock copolymer having a tri-block (A-B-A) radial structure having from4-8 arms, (3) an oil, and (4) a bis-stearamide wax. In addition, thesealant composition may contain sulfur as a crosslinking agent. Thesealant provides for more flexibility at lower temperatures, such astemperatures lower than or equal to about 40° F.

In further embodiments, bundles of roofing shingles that includes aplurality of pairs of roofing shingles suitable for installing on roofsare provided. Each of the roofing shingles includes a tab portion, anupper headlap portion, a release tape positioned on a first portion ofthe shingle, and a sealant positioned on second portion of the shingle.The shingles in the pairs are positioned such that the sealant on afirst shingle of the pair aligns with the release tape of a secondshingle in the pair. In exemplary embodiments, the release tape ispositioned on a rear portion of the headlap portion and the sealantcomposition is positioned a rear portion of the tab portion. The sealantreleases the first shingle from the second shingle in said pair. Thesealant composition includes (1) a hydrocarbonaceous material, (2) alinear copolymer having an A-B di-block or an A-B-A tri-block structureand/or a radial copolymer that is selected from a block copolymer havingan (A-B)_(n) radial structure where n is an integer of at least 4 and ablock copolymer having a tri-block (A-B-A) radial structure having from4-8 arms, (3) an oil, and (4) a bis-stearamide wax.

It is an advantage of the present inventions that the asphaltic sealantseals shingles at temperatures lower than conventional sealants.

It is another advantage of the present inventions that the inclusion ofwax reduces high temperature aggressiveness without adversely affectingbonding performance.

It is a further advantage of the present inventions that the sealantprovides for more flexibility at lower temperatures, such astemperatures lower than or equal to about 40° F.

It is also an advantage of the present inventions that the sealantimproves adhesion without adversely affecting the physical andperformance properties of the asphalt.

It is also an advantage of the present inventions that the sealantcomposition does not pose any safety or health issues to workersinvolved in their manufacture and/or application.

It is another advantage of the present inventions that the performanceof the adhesive sealant composition is sustainable over time.

It is also an advantage of the present inventions that the asphalticadhesive is useful in winter applications and in colder climates.

It is yet another advantage of the present inventions that the sealanthas excellent bead shape retention.

The foregoing and other objects, features, and advantages of theinventions will appear more fully hereinafter from a consideration ofthe detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of these inventions will be apparent upon considerationof the following detailed disclosure of the invention, especially whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic top plan view of a front view of a shinglesuitable for use in the present invention depicting the nail strip towhich the sealant adheres;

FIG. 2 is a schematic top plan view of the back side of the shingle ofFIG. 1 depicting the positioning of the sealant and the release strip;and

FIG. 3 is a schematic illustration of a pair of shingles used to form astacked bundle of shingles for shipping and/or storing.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the invention belongs. All references cited herein,including published or corresponding U.S. or foreign patentapplications, issued U.S. or foreign patents, or any other references,are each incorporated by reference in their entireties, including alldata, tables, figures, and text presented in the cited references. Theterms “sealant”, “sealant composition”, “adhesive sealant composition”,“inventive sealant”, “inventive sealant composition”, “asphaltic sealantcomposition” and “roofing sealant composition” may be interchangeablyused herein.

The present invention relates to an asphaltic sealant composition forroofing shingles that includes a base asphalt, a linear copolymer and/ora radial copolymer, an oil, and a wax, and optionally one or morefillers. The adhesive sealant seals at temperatures lower thanconventional sealants and permits the shingle to be easily removed froma packaged bundle of shingles. The inclusion of the wax in the asphalticsealant composition permits the release of the shingle from the releasetape of the adjacent shingle in the bundle without impacting the abilityof the shingle to bond to another shingle when applied to a roof.Although the sealant effectively seals at higher roof temperatures, itmay be particularly useful in winter applications and in cold, northernclimates. In addition, the adhesive sealant provides good resistance toshingle lift-up and flexibility at lower temperatures, such astemperatures lower than or equal to about 40° F.

The sealant contains, as one component, a base asphalt or otherhydrocarbonaceous material. As used herein, the term “asphalt” is meantto include any of a variety of materials that are solid or semi-solidmaterials at room temperature that gradually liquefy when heated and areformed predominantly of naturally occurring bitumens obtained as residuein petroleum refining. The base asphalt used in the inventive sealantcomposition is desirably a viscosity graded asphalt, such as AC-10 orAC-20, or a paving graded asphalt, such as PG58 or PG64, which arecommercially available from British Petroleum and Conoco Philips. Thebase asphalt may be generally present in the sealant composition in anamount from about 74.0% to about 90.5% by weight of the composition. Insome embodiments, the base asphalt may be present in the sealantcomposition in an amount from about 81% to about 88% by weight of thecomposition. As used herein, and unless defined otherwise, the phrase “%by weight” is meant to denote % by weight of the total sealantcomposition.

As discussed above, the sealant composition contains a linear copolymerand/or a radial copolymer, each of which is described in detail below.The copolymers are thermoplastic and are selected for their ability toimpart strength to the sealant at colder temperatures. As withconventional thermoplastic organic polymers, the copolymers used in theinventive sealant can be processed (i.e., melted and extruded) and canbe repeatedly heated and cooled with no substantial loss in theirproperties, including elastomeric properties. Accordingly, thecopolymers used herein substantially retain their properties whensubjected to heating and cooling cycles. One particular advantageousfeature is the ability of the copolymers to retain strength upon coolingthe copolymers, which gives strength and flexibility to the sealant atcolder temperatures.

The adhesive sealant composition contains a linear copolymer having anA-B di-block or an A-B-A tri-block structure. In particular, the linearcopolymer has a di-block content greater than 50%. Blocks A and B mayindividually represent (1) styrene and butadiene or (2) styrene andisoprene. Either block, A or B, may include more than one monomer.Additionally, each block segment may include 100 or more monomer units.The linear copolymer may have a styrene content of less than 50%, orfrom about 20% to about 40% styrene, or from about 20% to about 35%styrene. In some exemplary embodiments, the linear copolymer has astyrene/butadiene ratio of 33/67. In some examples the linear copolymerhas styrene or polystyrene as the A block or end block units. Suitablecopolymers include styrene-butadiene block copolymers andstyrene-isoprene block copolymers. Specific, non-limiting examplesinclude D1118K, a styrene-butadiene-styrene di-block copolymer, andD1113K, and D1119K, styrene-isoprene-styrene linear polymers with ahigh-di-block content (all are commercially available from Kraton®). Insome embodiments, the linear copolymer is a styrene-butadiene di-blockcopolymer, such as D1118K, commercially available from Kraton®. Thelinear di-block copolymer may be present in the inventive sealantcomposition in an amount from about 2.5% to about 11.0% by weight of thecomposition. In other embodiments, the linear copolymer is present inthe sealant composition in an amount from about 2.5% to about 6.5% byweight of the composition. In some exemplary embodiments, the linearcopolymer may be present in the sealant composition in a greater amount,such as, for example, from about 10-14% by weight of the composition, orfrom 11.0-12.0% by weight.

The radial copolymer may have an (A-B)_(n) radial structure, where n isan integer of at least 4, or from 4-20, or a tri-block (A-B-A) radialstructure having from 4-8 arms. Block copolymers are well known and aredescribed in numerous patents, including, for example, U.S. Pat. No.4,738,884 to Algrim, et al., U.S. Pat. No. 4,824,880 to Algrim, et al.,and U.S. Pat. No. 6,759,454 to Stephens, et al., each of which isincorporated by reference in their entirety. Similar to the linearcopolymer, block A and/or B in the radial copolymer may include morethan one monomer and each block segment may include 100 or more monomerunits. Additionally, blocks A and B may individually represent (1)styrene and butadiene or (2) styrene and isoprene. It is desirable thatthe radial polymer have styrene or polystyrene as the A block or endblock units. The radial copolymer may have a styrene content of lessthan 50%, or from about 20% to about 40% styrene, or from about 20% toabout 35% styrene. In some embodiments, the styrene/butadiene ratio is31/69.

Exemplary radial copolymers include D4158K (includes 33% oil), D1184K,D1116K, and D1144K, all of which are styrene-butadiene-styrene (SBS)radial copolymers (commercially available from Kraton®), and D1124K andD1126P, both of which are styrene-isoprene radial copolymers(commercially available from Kraton®). In some embodiments, the radialcopolymer is a styrene-butadiene radial copolymer, such as D4158K orD1184K (commercially available from Kraton®). The radial copolymer maybe present in the adhesive sealant composition in an amount from 0% toabout 9.0% by weight of the composition. In exemplary embodiments, theradial copolymer may be present in the sealant composition in an amountfrom about 3.5% to about 7.0% by weight of the composition.

When both a linear and a radial copolymer are present in the inventivesealant, the total amount of the radial copolymer and the linearcopolymer present in the sealant composition may range from about 6.5%to about 14.0%, or from about 8.0% to about 11.0% of the totalcomposition. Additionally, the ratio of radial copolymer to linearcopolymer present in the adhesive sealant composition may range from 6:3to 2:6 (radial copolymer:linear copolymer). In some embodiments, theratio of radial copolymer to linear copolymer present in the sealantcomposition is 5:4.

Another component present in the sealant composition is an oil. The oilcan be any oil recognized in the art to enhance the “softness” of theasphalt in the adhesive sealant composition. The oil also aids inreducing the viscosity of the sealant composition. In general, the oilis added in an amount necessary to achieve a desired viscosity for thesealant composition and to improve low temperature bonding. Theviscosity of the sealant composition desirably does not exceedapproximately 1500 cps as measured by a Brookfield LVF Viscometer usingspindle number 7 at 350° F. The oil utilized in the sealant compositionmay be a petroleum-based oil or other naphthenic or paraffinic oilsidentified by one of ordinary skill in the art. One particularly usefuloil is Hydrolene SP-125, a severely solvent modified heavy petroleum oilcommercially available from Sunoco, Inc. (CAS No. 63741-88-4). The oilmay be present in the adhesive sealant composition in a total amountfrom about 2.0% to about 7.0% of the total sealant composition, or fromabout 4.0% to about 6.0%. It is to be appreciated that a portion of thetotal oil content may be derived from another component of the sealantcomposition, such as, for example, an oil-containing copolymer.

A further component of the sealant composition is a wax. In someembodiments, the sealant composition is excessively aggressive at highertemperatures, such as temperatures above 110° F. It has beensurprisingly and unexpectedly discovered that the addition of anethylene bis-stearamide wax reduced high temperature aggressivenesswithout adversely affecting bonding performance. The wax may be abis-stearamide wax. These waxes have a unique and surprising property of“blooming” to the surface of the sealant, such as the sealant bead. Morespecifically, after the sealant has been applied to the appropriateportion of the shingle and the sealant begins to cool, the wax “blooms”to the surface of the sealant bead and crystallizes, forming a waxysurface to the bead. The wax functions to reduce the overall amount oftack at the surface of the sealant. In at least one exemplaryembodiment, the wax is an N, N′-ethylenebis-stearamide wax commerciallyavailable from Lonza, Inc. In exemplary embodiments, the wax may bepresent in an amount from about 0.2% to about 5.0% of the totalcomposition, from about 0.50% to about 3.0%, from about 0.5% to about3.0%, or from about 0.6% to about 2.5%, or from about 0.7% to about0.8%. In at least one embodiment, the wax is present in an amount ofabout 0.75% by weight of the total composition.

In some exemplary embodiments, fillers may be added to any of theadhesive roofing sealant compositions. For example, up to about 30% byweight of a filler may be used. Suitable fillers include, but are notlimited to, limestone (calcium carbonate), dolomite (calcium magnesiumcarbonate), wollastonite, talc, silica, and others known to thoseskilled in the art. The filler may have a median particle size fromabout 5 microns to about 50 microns, or from about 10 microns to about30 microns.

One asphaltic adhesive roofing sealant composition is set forth in Table1.

TABLE 1 Components of Roofing Alternate % By Shingle Sealant % By Weightof Weight of Composition Composition Composition PG64-22⁽¹⁾ 74.0-85.879.0-83.5 Kraton 1111⁽²⁾ 10.0-14.0 11.0-12.0 Hydrolene SP-125⁽³⁾ 4.0-7.05.0-6.0 Lonza EBS Wax⁽⁴⁾ 0.2-5.0 0.5-3.0 ⁽¹⁾performance grade asphalt(commercially available from British Petroleum and Conoco Philips)⁽²⁾styrene-isoprene-styrene tri-block copolymer (commercially availablefrom Kraton ®) ⁽⁴⁾petroleum-based oil (commercially available fromSunoco, Inc.) ⁽⁵⁾N,N′-ethylenebis-stearamide wax (commercially availablefrom Lonza, Inc.)

A second adhesive roofing sealant composition is set forth in Table 2.

TABLE 2 Components of Roofing Alternate % By Shingle Sealant % By Weightof Weight of Composition Composition Composition PG58-22⁽¹⁾ 74.5-88.378.0-85.5 Kraton 4158⁽²⁾ 5.55-8.55 6.3-7.8 Kraton 1118⁽³⁾ 4.6-7.65.6-7.6 Hydrolene SP-125⁽⁴⁾ 1.35-4.35 2.1-3.6 Lonza EBS Wax⁽⁵⁾ 0.2-5.00.5-3.0 ⁽¹⁾performance grade asphalt (commercially available fromBritish Petroleum and Conoco Philips) ⁽²⁾styrene-butadiene radialcopolymer containing oil (commercially available from Kraton ®)⁽³⁾styrene-butadiene di-block copolymer (commercially available fromKraton ®) ⁽⁴⁾petroleum-based oil (commercially available from Sunoco,Inc.) ⁽⁵⁾N,N′-ethylenebis-stearamide wax (commercially available fromLonza, Inc.)

A third adhesive roofing sealant composition set forth in Table 3. Theinventive sealant compositions described herein can be reacted withelemental sulfur to vulcanize in situ. Table 3 depicts an exemplarycomposition containing a mixture of two linear copolymers (i.e.,di-block and tri-block styrene-butadiene copolymers). After dispersionin the base asphalt and oil, the copolymer blend may be crosslinked withsulfur. The addition of the sulfur to polymer modified asphalts enhancesdispersion stability and improves mechanical properties.

TABLE 3 Components of Alternate % By Roofing Shingle % By Weight ofWeight of Sealant Composition Composition Composition PG64-22⁽¹⁾77.9-88.9 82.3-85.9 Kraton 1101⁽²⁾ 4.0-8.0 6.0-7.0 Kraton 1118⁽³⁾2.5-5.0 2.5-3.5 Hydrolene SP-125⁽⁴⁾ 4.0-7.0 5.0-6.0 Lonza EBS Wax⁽⁵⁾0.5-2.0 0.5-1.0 Elemental sulfur 0.1-0.3 0.1-0.2 ⁽¹⁾performance gradeasphalt (commercially available from British Petroleum and ConocoPhilips) ⁽²⁾styrene-butadiene-styrene linear tri-block copolymer(commercially available from Kraton ®) ⁽³⁾styrene-butadiene di-blockcopolymer (commercially available from Kraton ®) ⁽⁴⁾petroleum-based oil(commercially available from Sunoco, Inc.)⁽⁵⁾N,N′-ethylenebis-stearamide wax (commercially available from Lonza,Inc.)

Conventional mixing or blending techniques may be used to make thesealant composition. In at least one exemplary embodiment, the baseasphalt is heated to a temperature of approximately 350° F. and the oilis blended into the molten asphalt. A blend of the radial copolymer andlinear copolymer is added to the molten asphalt/oil to form a mixture.The mixture is then placed into a conventional milling apparatus wherethe polymers are sheared into smaller polymeric pieces. The mixture isground in the milling apparatus for a period of time sufficient to mill(grind) the polymers to a size that is no longer visible to the nakedeye when viewed as a thin film. The wax may be added to the asphalt/oilmixture after the polymeric blend is milled. The sealant composition iscooled for packaging and then melted for application to a shingle. Itmay be desirable to circulate and maintain the adhesive at an elevatedtemperature during processing and application to the shingles to aid inthe prevention of phase separation.

The sealant composition may be applied to any roofing shingle that isdesigned to be laid down in courses or layers, with at least a portionof successive layers of the shingles overlapping. The shingle may be anyconventional shingle known in the art; however, more particularly suitedshingles are those shingles made of glass fiber reinforced asphalt, suchas, but not limited to, the shingles described in U.S. PatentPublication No. 2007/0042158 to Belt, et al. For instance, the shinglemay be a granule covered roofing shingle having a lower tab portion, anupper headlap portion, a first end, and a second end. Such a shingle issuitable for installing on roofs end-to-end (or side-by-side) withsimilar shingles in overlapping longitudinal courses.

A non-limiting example of a shingle containing the inventive sealantcomposition is illustrated in FIGS. 1 and 2. The shingle 10 may includea headlap portion 12, a tab portion 14, and a nail strip 16 positionedat the interface of the headlap portion 12 and the tab portion 14. Inaddition, the shingle has a front side, depicted in FIG. 1 and a backside, depicted in FIG. 2. In exemplary embodiments, the sealantcomposition 18 is applied to the back side of the tab portion 14. Thesealant 18 may be applied to the shingle in any manner, and may take theform of a strip or a plurality of beads. A release strip or tape 20(e.g., silicone coated polyester film) is positioned on the back side ofthe headlap portion 12.

In use, the shingle 10 is placed on a roof (not shown) with the bottomside facing down towards the roof and is securely nailed to the roof bynailing or otherwise mechanically affixing the shingle 10 through thenail strip 16. A series of shingles 10 are placed on the roof in ahorizontal manner across the roof to form a first course of shingles. Asecond course of shingles is then affixed to the roof by positioningthese shingles over the first course of shingles such that the tabportion 14 of the shingles forming the second course overlaps theheadlap portion 12 and nail strip 16 of the first course of shingles.The shingles forming the second course are then nailed to the roofthough the nail strip 16 as described above. This process is repeateduntil the installer reaches the top of the roof The sealant 18 adheresthe tab portion 14 to the headlap portion 12 and/or the nail strip 16 ofthe shingle 10 in the course located directly below the shingle 10,thereby preventing “lift off” of the shingles 10 by high wind. In caseswhere there is an asphaltic coating to which the sealant adheres (notillustrated), the sealant also integrates into the asphaltic coating toprovide a mechanical adhesion as well as an adhesion by the componentsforming the sealant composition.

The sealant not only seals and adheres the shingles after placement ofthe shingles on the roof, the sealant improves the releasability of theshingles when the shingles are stacked or placed in a bundle, such asfor shipping and/or storing. The shingles 10 within the bundle arepositioned in pairs of two such that the sealant 18 lines up with therelease tape 20 of a previously positioned shingle, as depicted in FIG.3. In particular, the first shingle is positioned with the top surface11 of the shingle facing downward and the bottom surface 13 facingupward (i.e., the shingle 10 is flipped upside down). A second shingle,with the top surface 11 facing upward, is rotated 180° so that thesealant 18 of the second shingle aligns with the release tape 20 of thefirst shingle, and vice versa. In other words, the second shingle isoppositely oriented with respect to the first shingle to preventunwanted bonding of the shingles to each other within the bundle. Thethird shingle in the stack is placed in the same orientation as thefirst shingle so that the top surface of the second shingle is matchedagainst the top surface of the upside down third shingle. The fourthshingle is placed in the same orientation as the second shingle suchthat the sealant 18 of each of the third and fourth shingles aligns withan opposing release strip on the opposing shingle. This process isrepeated until enough pairs of shingles have been positioned to form thebundle for shipping and/or storing. These “paired” shingles may then bestacked and wrapped to form the shingle bundle.

As discussed above, the sealant may be applied to the shingle in anymanner, such as in a continuous strip or as a plurality of beads,dashes, other in some other discontinuous manner. The packaging orbundling of shingles having thereon conventional sealants may lead tosevere sticking of the shingles inside the bundle, even in the presenceof release tape. However, the inventive sealant improves the ability ofa worker to release the shingle from the bundle with relative ease. Thesealant functions within the package of shingles to prevent or reducethe occurrence of individual shingles adhering to each other within thebundle. Additionally, the adhesive improves flexibility and bonding,even at temperatures lower than or equal to about 40° F.

The sealant composition of the present invention provides numerousadvantages, such as, for example, the ability to provide a good initialbond during installation and to seal shingles at roof temperatures thatare lower than conventional sealants. It is also advantageous that thesealant composition permits the shingle to be easily removed from thepackaged shingle bundle. As discussed in detail above, the wax presentin the sealant composition forms a waxy surface on the sealant, whichallows for a quick and easy release from the release tape of theadjacent shingle in the package of shingles. The sealant formulationprovides lower sealing temperatures than traditional sealants, andmaintains excellent flexibility at low temperatures. Additionally, thewax causes the sealant composition to possess excellent bead shaperetention compared to identical formulations with no wax additive. Also,the sealant composition has little or no toxicity or safety issues, and,as a result, no additional safety precautions or equipment are needed toapply the sealant to a roofing shingle.

Having generally described this invention, a further understanding canbe obtained by reference to certain specific examples illustrated belowwhich are provided for purposes of illustration only and are notintended to be all inclusive or limiting unless otherwise specified.

Example

Materials Required:

Aluminum Panel (˜6″×3″)

PET film (Cut into pieces 6″ long)

Small (6″×6″) heated press (w/1 mm shims) set @ 260° F.

Adhesive Roller (10 pound) (preheated to 140° F.)

Silicone Release Paper

Oven @ 140° F.

Refrigerator @ 40° F. (or variable down to 0° F.)

Sealant or Adhesive (both unknowns and controls)

Procedure:

20 g of molten adhesive was poured onto an 8″×8″ piece of siliconerelease paper such that the adhesive was on one half of the paper, notin the center (so the paper can be folded in half prior to pressing).The material was allowed to cool for at least 20 minutes. Next, thepaper was folded in half so that one half of the paper covered theadhesive. The folded paper was then placed into a press and presseduntil the shims were contacted. The material was permitted to sit in thepress for approximately 1 minute. The pressure was then released and thepaper was removed.

The folded, pressed paper was placed into a refrigerator atapproximately 40° F. for about 10 minutes to allow the adhesive to cool.Immediately after removing the paper from the refrigerator, the paperwas cut into 4 strips having a size of 1 cm×6 cm. The release paper wasthen removed from the cut strips. Next, two strips were placed on analuminum panel about 5 mm from the edge. One piece of polyethyleneterephthalate (PET) film was centered over the adhesive strip such theedges of the film did not overlap the center of the panel. The panelswere then placed into an oven, taking care not to remove the tape.

After 30 minutes in the oven, one panel at a time was removed along witha pre-heated 10 pound roller. The roller was manually rolled over eachstrip (individually four times—2 up and 2 back). This rolling processwas repeated for all panels in the oven. Once the panels were pressed,the panels were all placed into the refrigerator at a pre-selectedtemperature for a period of not less than 12 hours and not more than 18hours. The time for each panel was recorded. After the allotted periodof time, each panel was removed and the tape was manually removed.Observations regarding the panel, tape, and releasability, as well asany other visual or physical observations of the inventive sealants,were noted and recorded.

The releasability of the panels was rated on a scale of 1 to 5 asfollows:

5: The tape showed strong bond showing no adhesive or cohesive failure.PET tape could not be removed

4: The tape showed initial bonding requiring some effort to pull apart.Once bond was broken, there was evidence of cohesive failure (someadhesive left on the tape).

3: The tape showed initial bonding requiring moderate effort to pullapart. Once the bond was broken, the tape showed adhesive failure.

2: The tape showed initial bonding requiring little effort to pullapart. Once bond was broken, the tape showed adhesive failure.

1: The tape showed no initial bonding. The tape peeled off with verylittle effort.

The observation collected recorded are set forth in Table 5.

TABLE 5 Wax Level (%) Peel Strength Control 0 1 Adhesive 1 0 4 Adhesive1 1.5 2 Adhesive 1 3..0 1 Adhesive 2 0 4.1 Adhesive 2 0.5 2.8 Adhesive 20.75 1.9 Adhesive 2 1.25 2.1 Adhesive 2 1.75 2.3 Adhesive 2 2.25 1.8Adhesive 3 0 3.25 Adhesive 3 0.5 3.0 Adhesive 3 0.75 4.125 Adhesive 31.25 3.25 Adhesive 3 1.75 2.875 Adhesive 3 2.25 2.0 Adhesive 4 0 4.5Adhesive 4 0.75 3.8 Adhesive 5 0 4.7 Adhesive 5 0.75 3.0

The control adhesive is a standard sealant formulation that is much lessaggressive compared to the inventive sealant formulation. Thisexperiment was designed to simply describe the performance of severalvariations of the inventive sealant with respect to adhesion to asimple, unmodified polyester film. The temperature was lowered to allowfor differentiation between sealants as well as to understand the impactof temperature on sealant flexibility. Although subjective, theexperiment shows that aggressiveness toward the film can be modifiedsubstantially with addition of wax. In addition, visual inspection ofthe sealant strips containing the wax shows a significant reduction inglossiness of the surface as compared to the samples that did notcontain wax, confirming the blooming of the wax to the surface of theadhesive strip.

The invention of this application has been described above bothgenerically and with regard to specific embodiments. Therefore, it is tobe understood that a wide variety of alternatives known to those ofskill in the art can be selected within the generic disclosure.

1. A composition for a sealant for a roofing shingle comprising: ahydrocarbonaceous material; a copolymer selected from a linearcopolymer, a radial copolymer and combinations thereof, said linearcopolymer and said radial copolymer being present in said composition ina total amount of at least 6 weight percent; an oil; and abis-stearamide wax, wherein said composition reduces the occurrence ofsaid roofing shingles adhering to each other within a packaged bundle ofshingles.
 2. The composition of claim 1, wherein said linear copolymerhas an A-B di-block or an A-B-A tri-block structure, and wherein saidradial copolymer is selected from a block copolymer having an (A-B)_(n)radial structure where n is an integer of at least 4 and a blockcopolymer having a tri-block (A-B-A) radial structure having from 4-8arms.
 3. The composition of claim 2, wherein said sealant seals attemperatures lower than conventional sealants.
 4. The composition ofclaim 1, wherein said radial copolymer is selected fromstyrene-butadiene-styrene (SBS) radial copolymers andstyrene-isoprene-styrene (SIS) radial copolymers; and wherein thecopolymer forming said linear copolymer is selected fromstyrene-butadiene block copolymers and styrene-isoprene blockcopolymers.
 5. The composition of claim 4, wherein said radial copolymerand said linear copolymer have a styrene content of less than 50%. 6.The composition of claim 1, wherein said oil is selected frompetroleum-based oils, naphthenic oils, paraffinic oils and combinationsthereof.
 7. The composition of claim 1, further comprising up to 30% ofone or more fillers selected from calcium carbonate, dolomite,wollastonite, talc and silica.
 8. The composition of claim 1, wherein:said hydrocarbonaceous material is an asphalt and said asphalt ispresent in said sealant composition in an amount from about 74.0% toabout 90.5% by weight of said composition; said radial copolymer ispresent in said sealant composition in an amount from 0% to about 9.0%by weight of said composition; said linear copolymer is present in saidsealant composition in an amount from about 2.5% to about 11.0% byweight of said composition; said oil is present in said sealantcomposition in an amount from about 2.0% to about 7.0% by weight of saidcomposition; and said wax is present in said sealant composition in anamount from about 0.2% to about 5.0% by weight of said composition.
 9. Aroofing shingle comprising: a tab portion and an upper headlap portion,said shingle being suitable for installing on roofs; a release tapepositioned on a rear portion of said headlap portion; and a sealantcomposition positioned on a rear portion of said tab portion, saidsealant composition including: a hydrocarbonaceous material; a copolymerselected from a linear copolymer, a radial copolymer and combinationsthereof, said linear copolymer and said radial copolymer being presentin said composition in a total amount of at least 6 weight percent; anoil; and a bis-stearamide wax, wherein said linear copolymer has an A-Bdi-block or an A-B-A tri-block structure, and wherein said radialcopolymer is selected from a block copolymer having an (A-B)_(n) radialstructure where n is an integer of at least 4 and a block copolymerhaving a tri-block (A-B-A) radial structure having from 4-8 arms. 10.The roofing shingle of claim 9, wherein said radial copolymer and saidlinear copolymer have a styrene content of less than 50%.
 11. Theroofing shingle of claim 9, wherein said oil is selected frompetroleum-based oils, naphthenic oils, paraffinic oils and combinationsthereof.
 12. The roofing shingle of claim 9, further comprising up to30% of one or more fillers selected from calcium carbonate, dolomite,wollastonite, talc and silica.
 13. The roofing shingle of claim 9,wherein said sealant composition reduces the occurrence of said roofingshingles adhering to each other within a packaged bundle of shingles.14. The roofing shingle of claim 9, wherein said sealant compositionfurther comprises sulfur as a crosslinking agent.
 15. A bundle ofroofing shingles comprising: a plurality of pairs of roofing shinglessuitable for installing on roofs, each of said roofing shingles in saidpair including: a tab portion and an upper headlap portion; a releasetape positioned on a first portion of said shingle; and a sealantpositioned on second portion of said shingle, wherein said shingles insaid pair are positioned such that said sealant on a first shingle ofsaid pair aligns with said release tape of a second shingle in saidpair, and wherein said sealant reduces the occurrence of said pairs ofroofing shingles bonding to each other within said bundle.
 16. Thebundle of claim 15, wherein said sealant releases said first shingle insaid pair from said second shingle in said pair.
 17. The bundle of claim15, wherein said release tape is positioned on a rear portion of saidheadlap portion.
 18. The bundle of claim 17, wherein said sealantcomposition is positioned a rear portion of said tab portion.
 19. Thebundle of claim 15, wherein said sealant is formed of a compositioncomprising: a hydrocarbonaceous material; a copolymer selected from alinear copolymer, a radial copolymer and combinations thereof, saidlinear copolymer and said radial copolymer being present in saidcomposition in a total amount of at least 6 weight percent; an oil; anda bis-stearamide wax, wherein said wax forms a releasable surface onsaid sealant to reduce the occurrence of said pairs of roofing shinglesbonding to each other within said bundle.
 20. The bundle of claim 15,wherein said linear copolymer has an A-B di-block or an A-B-A tri-blockstructure, and wherein said radial copolymer is selected from a blockcopolymer having an (A-B)_(n) radial structure where n is an integer ofat least 4 and a block copolymer having a tri-block (A-B-A) radialstructure having from 4-8 arms.